We present the preliminary Re-Os data from W-(Sn) granite-related mineralization hosted in phyllites near Jermanice, Bohemian Massif, Czech Republic. Analyzed samples JerB-1 and JerC-1 have very low Re and Os contents (23 and 54 ppt; 0.15 and 0.5 ppb, respectively) coupled with surprisingly strongly subchondritic Os-187/Os-188 between 0.1040 and 0.1054.
These preliminary results may suggest unique behavior of wolframite with respect to Re-Os isotopic system. While the Os contents are similar to terrestrial basalts e.g., MORB etc.), it shows much lower Re contents and (OS)-O-187/Os-188 similar to Martian meteorites (SNC) and Eucrite Nuevo Laredo.
Therefore, it is possible that wolframites have a potential to retain primary, frozen Re-Os composition reflecting Re-Os composition of the primordial Earth's mantle.